60 MISS J. DONALD ON THE GENUS ACLISINA. [Feb. 1 8 98, 



the lines of growth distinctly. One is figured (PI. IV, fig. 5) ; it 

 consists of five and a half whorls, of which the length =3|- mm. 

 A specimen from Law in Mr. Bennie's collection possesses fifteen 

 whork in a length of 4^ mm. ; it shows the reflection of the 

 inner lip. 



ACLISINA GEANTONENSIS, sp. nOV. (PI. IV, figS. 7-9.) 



Murchisonia striatula, De Kon. ?, R. Etheridge, Jun., ' Invert. Fauna Lower Carb. 

 •or Calcif. Sandst. Series of Edinburgh, etc' Quart. Journ. Geol. Soc. vol. xxxiv 

 (1878) p. 19 & pi. ii, fig. 29. 



Description. — Shell minute, elongated, conical, composed of about 

 ten whorls. Protoconch consisting of about one smooth whorl, 

 partly detached, and forming a considerable angle with the highest 

 whorl of the spire. Whorls convex, slightly flattened above, and 

 more or less angular and prominent near the middle. The lower 

 two-thirds of each whorl ornamented by about nine raised threads, 

 alternately coarse and fine ; upper third apparently smooth. Lines 

 of growth distinct, strongly sigmoidal, curving forward below. 

 Sutures deep. Aperture subovoid. Columella simple, nearly 

 straight. Base convex, imperforate. 



Resemblances. — This shell was referred, with a query, by E. 

 Etheridge, Jun., to Murchisonia striatula^ De E.on., but it is quite 

 distinct, being much smaller, having the lines of growth sigmoidal 

 instead of forming a narrow sinus in the outer lip, and the proto- 

 conch also of difi'erent form. It most resembles A. tenuistriata ; the 

 whorls, however, are less convex, and the fine threads with which it 

 is ornamented do not form bands, but alternate more or less regularly 

 with the coarser threads. It is remarkable for having the proto- 

 conch well preserved, there being eighteen specimens showing it in. 

 Mr. Bennie's collection. Its junction with the conch can generally 

 be discerned, but the surface is too much worn to show where the 

 ornamentation begins. The form of the protoconch resembles that 

 of A. pulchra var. tenuis. 



Dimensions. — The specimen figured (PI. IV, fig. 7) consists of ten 

 whorls, whose length =4 mm. and width =1$ mm. ; it is in the 

 Geological Survey Collection, Museum of Science & Art, Edinburgh, 

 where six more examples are shown. The same museum contains 

 the specimen figured by Mr. Etheridge and two others in the 

 General Collection. Other individuals would be larger if entire ; 

 one in Mr. Bennie's collection has five whorls in a length of 3| mm., 

 and its width = If mm. The protoconch is figured (PI. IV, 

 figs. 9 a, 5 & c) from shells in his collection. 



Locality and Horizon. — It is very abundant in the Calciferous 

 Sandstone Series (d-) at Woodhall, near Edinburgh. 



ACLISINA TENUISTRIATA, Sp. noV. (PI. IV, fig. 10.) 



Aclisina striatula, J. Donald, 1885, ' Carb. Gaster. from Penton, etc' Trans. 

 Cumberl. & Westmorl. Assoc, no. ix, p. 131 & pi. ii,figs. 2 & 2a. 



Description. — Shell small, conical, composed of about ten convex 



